Saint Marys pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Saint Marys is moderate; ragweed is moderate; grass and mugwort are low.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed declining, grass no longer expected, mugwort no longer expected.
7-Day Trend
Over the next week grass, mugwort, and ragweed will increase.
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Pollen Risk
Today - 20 September
| Pollen species | Level | Value |
|---|---|---|
| Alder (Alnus) | None | 0/100 |
| Birch (Betula) | None | 0/100 |
| Hazel (Corylus) | None | 0/100 |
| Cypress (Cupressaceae) | None | 0/100 |
| Grass (Poaceae) | Low | 16/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 9/100 |
| Ragweed (Ambrosia) | Moderate | 42/100 |
Tomorrow - 21 September
| Pollen species | Level | Value | 7-Day Trend |
|---|---|---|---|
| Alder (Alnus) | None | 0/100 | — |
| Birch (Betula) | None | 0/100 | — |
| Hazel (Corylus) | None | 0/100 | — |
| Cypress (Cupressaceae) | None | 0/100 | — |
| Grass (Poaceae) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Low | 12/100 |
Local Environmental Conditions
Nearby, just outside the immediate area, the waterway's edge supports hazel and willow, species known for potent, wind-carried pollen. A wooded area built around oak and birch, both contributing heavily to the region's spring pollen totals, close to this spot. Actual counts still shift year to year with temperature, rainfall, and prevailing wind.
The waterside hazel and willow are consistently first to release pollen each year, getting an early start, typically cresting between February and March. Once hazel fades, oak and birch in the woods carry the season forward, reaching its high point through April and into May. Grass pollen counts rise through late spring, reaching their peak around June, handing off to ragweed, which peaks from mid-August through October.
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Frequently Asked Questions About Pollen in Pennsylvania
Is pollen high in Saint Marys right now?
On 20 September 2026, overall pollen levels in Saint Marys are moderate. Ambrosia is the main contributor to airborne pollen, while artemisia and grass remain at lower levels
Will pollen levels change in Saint Marys tomorrow?
On 21 September 2026, pollen conditions in Saint Marys will be different from today, with ambrosia continuing to decline
Is pollen expected to decrease in Saint Marys this week?
According to the five-day outlook, ambrosia, artemisia, and grass pollen levels will increase later in the week.
Which pollen types are currently active in Saint Marys?
On 20 September 2026, Ambrosia is the dominant pollen source in Saint Marys. artemisia and grass are also present but at lower levels.
When is pollen season in Saint Marys?
How often is the Saint Marys pollen forecast updated?
The Saint Marys pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Saint Marys come from nearby or far away?
Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.
Are pollen levels in Saint Marys based on measurements or forecasts?
Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.
Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in Saint Marys, modern forecasts combine recent measurements, weather data, and information about local vegetation.
This allows us to estimate pollen levels for today and the coming days, not just report the past.
Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.
Understanding the Scale
The 0–100 scores represent risk levels, not direct measurements of pollen or air pollutant concentrations. Higher scores indicate higher risk. Pollen and air quality use different thresholds.
Pollen
| None | 0 | No or negligible risk of exposure. Pollen/mold exposure is expected to be minimal. |
| Low | 0-25 | Low risk of exposure. Small amounts of pollen or mold spores may be present. |
| Moderate | 25-50 | Moderate risk of exposure. Pollen/mold exposure is expected to be noticeable. |
| High | 50-75 | High risk of exposure. Elevated pollen/mold exposure is expected. |
| Very High | 75-100 | Very high risk of exposure. Pollen/mold exposure is expected to be at or near its highest levels. |
Get More in the Airmine Pollen app
Get 15-day pollen forecasts with morning, afternoon and evening detail, plus 5-day air quality forecasts. Explore interactive pollen risk maps, estimated pollen season start, route profiles and a symptoms diary.
Features and forecast availability vary by region. Currently covering Europe, the contiguous US, southern Canada, South Africa, Australia, Indonesia (Java & Bali), Brazil, Paraguay, Uruguay and the Buenos Aires area.
Developed with support from the European Space Agency (ESA) Business Applications and Space Solutions (BASS).
